While downloading a resource pack is not illegal, how you use it can be problematic.
Most of these packs are 16x16 resolution, meaning they do not require a powerful computer or an external patcher (like Optifine) to work, though Optifine is recommended for the "Night Vision" effect often bundled with these packs. 1.12 2 xray resource pack download
Locate a reputable website (such as CurseForge, Planet Minecraft, or the official creator's site). Avoid generic "ad-fly" links that force you to watch ads, as these often lead to malware. While downloading a resource pack is not illegal,
: Often cited for its compatibility across older versions of Minecraft. 1.12 2 xray resource pack download